1. Field of the Invention
The present invention relates in general to displaying apparatuses, and in more particular, to a displaying apparatus capable of adjusting brightness, contrast and colors of images appearing on the screen of the displaying apparatus so as to be identical absolute colors thereof.
2. Description of the Related Art
Generally, a displaying apparatus receives synchronous signals and red, green and blue (RGB) color signals supplied from a video card installed on a computer main body and displays them in the form of images on the screen thereof. The displaying apparatus includes a cathode ray tube CRT) monitor employing vacuum tubes or a liquid crystal display (LCD) monitor, and so on.
If an electron beam is emitted within the CRT monitor, the electron beam is bent by horizontal and vertical deflecting coils to strike a point on the screen. The inner surface of the screen is coated with phosphor, which emits lights if the beam is received therein. Since the electron beam continuously strikes each point on the screen, lights are emitted depending upon contact of the beam with the respective points, thereby displaying images on the screen.
The LCD monitor uses a property that if a voltage is applied to a liquid crystal layer stored in a space between two thin glass plates through a transparent electrode, a direction of orientation of the molecules of the liquid crystal is changed, and then the rate of light passing through the liquid crystal layer is changed. Usually, the liquid crystal in itself does not emit lights. A portion of the liquid crystal, to which a voltage is applied when lights are reflected by a reflecting plate in the backside thereof, becomes opaque, thereby making it unavailable for reflecting images. Because of this, the images are differentiated in brightness. The colors displayed on the screen of a display device often vary not only between different models of display devices, but also between different display devices of the same model. Efforts have been made in the art to calibrate individual display device in an effort to obtain uniformity between their colors. Frequently the black point is obtained by adjusting the whiteness in contrast of the monitor relative to an external, hand-held color card containing a black image. The color card must be present and used for each adjusting of the display device. Efforts such as the Interactive Method And System For Color Characterization And Calibration Of Display Device by Peter Engeldrum et al., U.S. Pat. No. 5,638,117, is an exemplar of the adjustment of the color in a central portion relative to a peripheral area by using a visual comparison between one or more matching cards viewed in juxtaposition to an image displayed on the screen of the display device.
The Method And Apparatus For Adjusting Television Display Control Using A Browser by T. A. Bruck, et al., U.S. Pat. No. 6,008,836, relies upon the user's adjustment of brightness in an effort to render an image within a colored box projected upon the screen, barely visible. This algorithm for executing this technique must be downloaded via WEB-TV from a web server.
The Color Calibration Of Display Device by J. M. Sach, U.S. Pat. No. 5,483,259, relies upon adjustment of the brightness control until a black area and an adjacent dark gray area become indistinguishable.
Japanese patent publication No. Heisei 08-194452, assigned to Canon, requires a user to adjust the color of the central portion of the screen to match peripheral patterns by using a keyboard, but lacks adjustment to obtain calibration of black points and white points.
The Display Calibration of A. D. Edgar, et al., U.S. Pat. No. 5,298,993, relies upon adjustment of the brightness by using a grid pattern, with adjacent patterns controlled to provide a continuous tone.
The Apparatus For Determining A Black Point On A Display Unit And Method Of Performing The Same by K. Ohara et al., U.S. Pat. No. 6,084,564, endeavors to facilitate a determination of a black point by setting a comparison brightness region in order to allow an easy distinction relative to a reference brightness region. A gamma point is controlled by using a standard region and a control region.
The Printer Calibration by Michael J. Vigneau, et al., U.S. Pat. No. 6,008,907, uses a pattern in an effort to adjust the color of the printed image to the display image formed on the screen of the display device.
Despite these efforts in the art, I have encountered significant problems attributable to color mismatch between peripheral devices, for example, monitors, printers, digital cameras, color scanners, and other appliances, and have recognized the need for a color management system that provides accurate and predicable color matching, and is available for use with any type of monitor as well as multi-monitor setups.